‘‘We’re only a small town, but I’m not too worried because we can’t see the smoke from where I am.’’

Ms Zikich said she believed the razed house was not occupied at the time of the fire because the homeowner had died late last year.

A strong wind change is expected to fan the ferocity of other fires burning across Victoria.

Firefighters battling flare-ups at the scene of a 55,000-hectare bushfire in the Grampians say the sudden weather change could escalate the threat to residents in the region.

The south-westerly wind change from about 6pm and temperatures above 40 degrees in the state’s west may lead to spot fires and erratic fire behaviour.

The State Control Centre said the fire was at risk of spreading through other parts of the Grampians area, and an advice message has been issued to residents of Halls Gap and towns to the east of the Grampians.

‘‘The fire status is contained, but there is still active fire within the fire perimeter and residents need to remain vigilant and alert,’’ the warning said.

Earlier this month, a large bushfire sparked by lightening tore through the Grampians and destroyed more than 30 homes.

The January 15 fire burnt razed more than 135 structures, destroyed national park infrastructure and killed more than 3000 sheep.

Livestock assessors and a wildlife welfare team are continuing to assess damages.

More than 15 fire crews are battling an out-of-control fire in Gippsland.

The fire began in bushland at Leongatha shortly after 4.40pm, but soon spread to nearby grassland.

Authorities say there are no threat to homes or property.

There were at least 23 active fires burning in Victoria on Tuesday.

The Country Fire Authority has issued a total fire ban across the state, as weather conditions range from high to extreme.

A state control centre spokesman said the Mallee, Wimmera, South West, Northern Country and Central regions have all been issued severe and extreme warnings.

Commuters faced delays

It was a long journey home for many Melbourne commuters on Tuesday, as the mercury hit 42 degrees while suburban trains faced 15-minute delays.

Metro advised there would be delays of up to 15 minutes after speed restrictions were put in place on Tuesday afternoon.

Metro spokeswoman Larisa Tait said there were a range of delays on rail lines including Pakenham, Cranbourne, Werribee, Sunbury and Craigieburn.

She said residents of outer-metropolitan areas would be worst-affected.

But she said there had been no other "major" delays across the rail network during the afternoon hot spell.

Metro announced the restrictions before the temperature hit 38 degrees about 3pm.

During the heatwave two weeks ago, Metro brought in speed restrictions of 70km/h across the network and urged commuters to leave the city before the afternoon rush.

V/Line trains on all lines will run at slower speeds until 8pm Tuesday, with the operator also enforcing heat speed restrictions.

V/Line is advising customers to allow an extra 20 minutes travel time for their commute.

Trains to and from Swan Hill, Echuca, Bendigo, Albury / Wodonga and Shepparton are are expected to be the worst affected.

"Cancellations have only affected a handful of counter peak trains according to the heat timetables in place," a spokesman said.

Ambulance warning

Frustrated paramedics have been called to 14 cases of children locked in cars on Tuesday, as the temperature climbed to 42 degrees.

Ambulance spokesman Rob Clancy said four instances of children locked in cars had resulted in four emergency triple-0 calls with a 12-minute period.

One was in Essendon Fields shopping centre and others were in Ferntree Gully, Mornington, Oakleigh East, Geelong, Warragul, Torquay, Wodonga and Ravenhall.

Paramedics also responded to 41 cases of heat stress and exhaustion on Tuesday, Mr Clancy said.

Earlier, Paul Holman, an operations manager at Ambulance Victoria, urged people not to leave anyone in a car in hot weather.

‘‘It is just the most dangerous thing you can do,’’ he said. ‘‘Look after yourselves, look after your families, look after your children.’’

Mr Holman said Ambulance Victoria was preparing to roster on extra paramedics this weekend to deal with increased demand for care among people affected by the heat.

He said people should make sure they monitor and care for elderly people, the infirm and those with chronic illnesses to make sure they are well hydrated and cool.

‘‘Check on them,’’ he said. ‘‘We had some tragedies last week where people were left alone and they were found alone.’’

Firebug hunt

In a separate incident, police are hunting two teenagers who they believe may be responsible for deliberately lighting a grass fire in Epping last Tuesday.

Although the blaze was quickly extinguished and did not damage surrounding houses and businesses, police would like to talk to a teenage boy, girl and another small boy who were seen walking through the grassland just before the blaze started off Harvest Home Road, Epping, about 3pm.

Anyone with information is asked to phone Crime Stoppers on 1800 333 000.